1. Field of the Invention
The present invention is directed to a device for accepting an ultrasonic transducer having an acoustic axis, the device being attachable to a therapeutic head that contains means for generating acoustic waves converging in a focus, the device allowing the ultrasonic transducer to be attached at the device such that its acoustic axis proceeds substantially through the focus of the therapeutic head. The invention is also directed to the combination of a therapeutic head and such a device.
2. Description of the Prior Art
German PS 39 15 384 discloses a device of the general type described above. The device has a ring, which is arranged at the therapeutic head and which can be rotated around the therapeutic head; the rotational axis of the ring coinciding with the acoustic axis of the therapeutic head. A lever arm with three levers that can be rotated around rotational axes is arranged at the ring, this lever arm guiding the ultrasonic transducer in a restricted manner such that the ultrasonic transducer is always aimed at the focus of the therapeutic head given rotations of the ring around its rotational axis and given slewing motions of the levers of the lever arm around their rotational axes.
The advantage of such an arrangement for guidance of an ultrasonic transducer relative to a therapeutic head is that, for example, the orientation of the focus of the therapeutic head of a lithotripter provided with such a device toward a calculus, which is to be disintegrated in the body of a living organism, is facilitated, since the acoustic axis of the ultrasonic transducer is always directed toward the focus of the therapeutic head independently of adjustment motions or scan motions of the ultrasonic transducer with the device for the purpose of locating the calculus within the body by ultrasound. In this way, the focus of the therapeutic head can be displaced in a simple way under ultrasonic control relative to the calculus to be disintegrated with focused acoustic waves, by means of adjusting the therapeutic head relative to the living organism.
German PS 34 27 001 describes a therapeutic device for the contact-free disintegration of calculi in the body of a patient, which has a shockwave focusing chamber arranged in a tub, in which a patient is seated, and which has a locating and positioning device, which is provided with an ultrasonic transducer and which can be adjusted relative to the focus of the shockwave focusing chamber. The locating and positioning device has a C-bend guide that can be positioned around the body of the patient. At this guide, the ultrasonic transducer can be displaced over a larger region of the body. For marking or registering the position or the position and the direction of the ultrasonic transducer with respect to the focus of the shockwave focusing chamber, corresponding devices are provided at the therapeutic device, for example, position sensors and/or angle transmitters.
Further, German OS 39 32 364 discloses a spherical-cap-shaped therapeutic transducer for use for disintegrating objects inside of the body. An ultrasonic transducer is integrated into the therapeutic transducer for locating the objects to be disintegrated, the ultrasonic transducer being adjusted in a confocal manner relative to the therapeutic transducer.
The technically complicated structures of these known devices represent a disadvantage.
An object of the present invention is to a device of the type described above having a structure that is technically simple and therefore inexpensive. A further object of the invention is to provide a therapeutic head such that the device can be variably arranged at the therapeutic head.
This object is inventively achieved in a device for movably holding an ultrasonic transducer having an acoustic axis, the device being attachable at a therapeutic head that contains means for generating acoustic waves converging in a focus, and having at least one element that can be swivelled around a swivel axis of the device, the ultrasonic transducer being mounted at the element such that its acoustic axis proceeds substantially through the focus of the therapeutic head when the device is attached at the therapeutic head, and wherein the swivel axis proceeds substantially through the focus of the therapeutic head when the device is attached at the therapeutic head. The inventive device has only one element at which the ultrasonic transducer is arranged and which can be swivelled around a swivel axis of the device. Therefore, the device is structured extremely simply and inexpensively. Preferably, the ultrasonic transducer is arranged at the element such that it can be displaced along its acoustic axis, so that it can be rested against the surface of a body of a living organism to be treated with acoustic waves. In this case, measuring elements that register displacements are preferably allocated to the ultrasonic transducer in order to enable an exact mixing of the position of the focus into the ultrasonic images acquired with the ultrasonic transducer given a displacement of the ultrasonic transducer. Because the swivel axis proceeds substantially through the focus of the therapeutic head given a device attached at the therapeutic head, the acoustic axis of the ultrasonic transducer also always proceeds substantially through the focus of the therapeutic head given swiveling of the element around the swivel axis. Therefore, the swivel of the element around the rotational axis enables positioning of the ultrasonic transducer, for example, when observing the disintegration process of a calculus in the body of a patient, at different locations of the body surface of the patient without losing the relation to the focus of the therapeutic head.
In a preferred embodiment of the invention the element is fashioned in a curved manner. According to a version of the invention, the bent element is substantially circularly curved, with the center of curvature of the bent element substantially coinciding with the focus of the therapeutic head given a device arranged at the therapeutic head.
In further versions of the invention provide that the ultrasonic transducer can be adjusted along the circumference of the bent element, or the ultrasonic transducer can be attached at a holding device, which is adjustable along the circumference of the bent element. Thus, the ultrasonic transducer can be adjusted in a practically spherical manner within a spherical segment by swivelling of the bent element around the swivel axis and by displacement of the ultrasonic transducer, or the holding device for the ultrasonic transducer along the circumference of the bent element. The device thus offers a number of possibilities for positioning the ultrasonic transducer with respect to the body surface of a patient to be examined and to be treated with acoustic waves.
In another embodiment of the invention, the bent element of the device has an opening in the form of a slot, this opening extending in the circumferential direction, and a holding device, for the ultrasonic transducer can be adjusted in the opening in the circumferential direction of the bent element. This structure of the device with a holding device for the ultrasonic transducer, with the holding device being adjustable in such an opening, effects a stabilization of the adjustment movement of the holding device and the ultrasonic transducer.
In a further version of the invention, the holding device is circularly curved at least in the area in which the ultrasonic transducer is arranged at the holding device, with the center of curvature of the holding device substantially coinciding with the focus of the therapeutic head when the device is attached at the therapeutic head. The ultrasonic transducer is preferably arranged adjustably in the holding device, or at the holding device. Thus, apart from the adjustment of the holding device of the ultrasonic transducer in the circumferential direction of the bent element, further adjustment possibilities are available for the ultrasonic transducer with respect to the body surface of a living organism to be treated with the therapeutic head, by adjusting the ultrasonic transducer in the circularly curved holding device, or at the circularly curved holding device. Inventively, the acoustic axis of the ultrasonic transducer is always directed substantially toward the focus as a result of the circular curvature of the bent element and the holding device.
In a further embodiment of the invention, a second bent element is provided, which is arranged essentially parallel to the first bent element, with the holding device connecting the two bent elements. A stabilization of the adjustment process of the holding device can also be effected in this way when the holding device is adjustable in the circumferential direction of the bent elements.
In another embodiment of the invention, at least one further element is provided, which element is connected to the first element preferably via a pivot having a swivel axis and which, relative to the first element, can be swivelled around this swivel axis of the pivot. Preferably, the first element and the further element are each fashioned in a bent, circularly curved manner. This embodiment of the invention makes it possible, for example, to turn the one element such that it rests substantially at the first bent element. Given the orientation of the focus of the therapeutic head toward a calculus to be disintegrated or toward a body tissue to be treated, the second bent element is preferably folded out and forms a bend with the first bent element, at which bend the ultrasonic transducer is adjustably arranged, for example, in the circumferential direction. During the examination process or therapy process, the second bent element can be turned around the rotational axis, so that a compact arrangement of the bent elements is achieved.
In a preferred embodiment of the invention, the first element and the second element can have a common swivel axis, which forms a second swivel axis of the device. The two elements can be adjusted relative to one another around this common swivel axis, which proceeds substantially through the focus of the therapeutic head given a device arranged at the therapeutic head. Preferably, the first element and the second element are each fashioned in a bent manner. For example, when the ultrasonic transducer can be arranged at the second bent element and the first bent element of the device can be additionally swivelled around the initially described swivel axis of the aforementioned device, making possible a spherical movement of the ultrasonic transducer within a spherical segment and thereby allowing variable positioning of the ultrasonic transducer relative to the body surface of a living organism to be treated.
In a further version of the invention a number of elements, which are preferably fashioned in a bent manner, and which are movable relative to one another, form a chain at which the ultrasonic transducer is arranged. These elements alternatively can be arranged in the form of a telescopic arm with the ultrasonic transducer fastened at one end. In another version of the invention the device has two spherically curved plates, which are arranged at the therapeutic head and whose centers of curvature substantially coincide with the focus of the therapeutic head given a device arranged at the therapeutic head. The plates contain an intermediate space therebetween with a substantially constant gap width in which the bent element is adjustably held. In this version, the ultrasonic transducer also can be moved relative to the therapeutic head in a technically simple way such that its acoustic axis always proceeds substantially extends through the focus of the therapeutic head.
The above object is also achieved in a therapeutic head which has at least two fastening arrangements that are appropriate for variably attaching a holder device as described above. Thus, the holder device can be fastened at at least two different locations of the therapeutic head, so that the ultrasonic transducer can be positioned relative to the body surface of a patient in multiple ways.